I would read the error message.
It said
"Error using filter2
N-D arrays are not supported."
So, first, is your array more than 2-dimensional? I would bet that it is, since it appears to be an image. filter2 applies ONLY to 2-dimensional arrays. You cannot force code to do that which it is not designed to do. You can pray that it will work, but prayer seems so rarely useful with computer programming languages.
Perhaps your thought is to apply filter2 to each image plane. So do it. A loop is surely easiest there, calling filter2 once for each plane.
